The present invention relates to an improved method of the chemiluminescence assay of the activity of peroxidase.
Recent research and development activities of enzyme immunoassay directed to the improvement of the sensitivity of the assay have been remarkable. Unquestionably the chemiluminescence assay is a useful means for achieving this object. For instance, it has been reported that a chemiluminescence assay using luminol has a peroxidase detection sensitivity of 10.sup.-16 mol (PNE, Nuclei Acid and Enzyme, Extra Issue No. 31, pages 51-63).
The peroxidase detection sensitivity attained by the above method is much higher than a detection sensitivity of 10.sup.-15 mol attained by a colorimetric peroxidase detection method using 2,2'-azino-di(3-ethylbenzthiazinolinesulfonate) ABTS as a substrate, and a detection sensitivity of 10.sup.-14 mol attained by a fluorescent peroxidase detection method using p-hydroxyphenyl propionic acid as a substrate.
However, the chemiluminescence assay is in fact not in general use since it has the shortcoming that the luminescent time is too short to be used in practice. Under such circumstances, a chemiluminescence assay using as p-iodophenol as an enhancer for the activity of peroxidase has been tried in an attempt to increase the detection sensitivity as reported in H. Allan, J. Microbiology Apr., 630-636, 35, 1988). This chemiluminescence assay has attained some improvement of the detection sensitivity but has the shortcoming that the reproducibility of the assay is so poor that obtained data is not always reliable.